Those trains are running perfectly fine on the great northern. yes, they're slightly different, but come on.

A bit more than slightly different, but that’s not the point.
The point is that the signals can’t be seen properly unless the train stops short of the platform edge, which then leaves a blind spot. Pain in the back side, but that’s the way it is, for the moment at least. Rumours flying around that there will be permanent solutions to this in the next few years or so